Seam finishing



J. P. DUNN SEAM FINISHING Nov. 7, 1967 2 Sheets-Sheet 1 Filed Dec. 4, 1964 q 1 l I I I I l I I I I I l I I l l {Ill 1 I LIIJ iiipj I1! lw h 3 V, 4 Ll 2 Fig.

iNVENTOR. J 0 /m P. 0 un n Fig. 2

ATTORNEY Nov. 7, 1967 J. P. DUNN 3,350,815

SEAM FINISHING Filed Dec. 4, 1964 2 Sheets-5heet 2 WNW BY MKFM ATTORNEY United States Patent 3,350,815 SEAM FINISHING John P. Dunn, Elmira, N.Y., assignor to Corning Glass Works, Corning, N.Y., a corporation of New York Filed Dec. 4, 1964, Ser. No. 416,087 2 Claims. (Cl. 517) ABSTRACT OF THE DISCLOSURE vibration or oscillation of the article relative to the charm ber by means of its flexible mounting.

It is inherent in machinery and molds utilized in the production of ware articles, such as glass-ceramic cups, to form an offset on the article surfaces. The said offset results from -a mismatch between two adjacent portions of a mold. On cup-shaped articles these offsets most frequently occur in lip-edge portions and handle portions. Flash may also occur in these areas. Often when the flash is broken away, a trough results. Deleterious finish irregularities, such as ofisets and troughs, must be removed before the article may be used as an eating utensil. The offsets must be smoothed to form rounded edges and the troughs must be blended into the natural contour of the article. i

In the past, it has been customary to remove the ofiset and flash from the edge portions of the articles by conventional fire-polishing methods, however, this method is completely unsatisfactory for finishing materials in newly developed glass-ceramics. If articles formed from glass-ceramics were fire-polished, areas in the locality of the fire-polishing would tend to partly devitrify. Further, since selected areas would be partially devitrified, it would be impossible to produce a uniform, acceptable glaze on the finished article.

Many commercially available tumbling and vibrating machines are acceptable for metal articles. These machines are used for deburring, scale removing, surface treating, and coloring. Some stock removal does occur but this is not the primary function of these machines. A conventional process normally consists of a chamber filled with pellets or media, parts to be treated, wetting agents, rust inhibitors, and on special occasions, loose abrasives.

The parts are sometimes fastened or fixtured to a cover plate but normally they are free to rotate in the media 'and other additives. Allowing glass-ceramic articles to rotate freely was unsatisfactory. Articles tended to group together in the chamber so that they scratched and nicked one another. Damage was often extensive enough to cause rejection.

The media can be made from almost any material, such as wood chips, metal shot or abrasive nuggets. The media particles can be considered as impact tools which apply the force necessary to do Work. Pellets can be preformed to a desired shape or can be a random shape. The media selection is usuallybased on the contour and composition of the articles to be finished.

Other known processes used to remove offsets and troughs proved unsuccessful. Oscillating hones presented a basic problem of centering on the finish irregularity.

That is, it was difiicult to locate the hone so that it accurately engaged the irregularity. A further problem was that any time a contour changed, a new hone configuration was required. Grit blasting proved unsatisfactory since the grit would deflect off the radius of a curved ware piece and knock the main stream of grit from a true course. As a result, more surface area than the irregular portion of the article would be hit. Centrifugal plunge grinding method was successful for stock removal, however, if the ware article broke while in the media, broken parts could not be removed.If the broken parts remained in the media, other ware articles became damaged.

Therefore, since the conventional finishing methods and apparatus could not be feasibly and economically utilized to remove the olfset and flash trough from glass-ceramic material, I devised a novel apparatus which solves these finishing problems and is commercially feasible.

A conventional vibratory process consists of an angular displacement of a mass and an oscillatory motion superimposed on this moving mass. Both of these motions can be summarized into a vector force which is transmitted to this mass through contact with a chamber wall or a fixed ware article. If the ware is not fastened to the chamber, the transmission of forces would be through the batch only. An increase in this force directed from, or to the media would increase the cutting rate on the glass-ceramic article.

Glass-ceramic removal as related to vibratory finishing, is directly proportional to a g force imparted to the media in the system. In standard vibratory systems this force is transmitted to an article by displacing the media at a set frequency or amplitude.

Batch is a mixture of media, compound and water. Media, such as nuggets, are in effect, impact tools which apply the force necessary to do the work. The term compound is used by the industry to describe mixtures of acid, alkaline, or neutral compounds with or Without loose abrasives. Examples or loose abrasives would include silicon carbide, alumina, garnet and sand. The compound is used to vary the cutting properties of the media while keeping the media functioning most efficiently.

Basically my invention includes a chamber of predetermined interior contour which permits a more uniform flow of a suitably excited media around a suitably mounted glass-ceramic ware article in order to improve selectively the quality of certain desired article surfaces. The contoured chamber concept was developed in order to reduce the quality of batch required to process a ware article.

It has thus been an object of my invention to provide a means for grinding an irregularly contoured article Without the necessity of special tooling.

It has been a further object of my invention to provide a means for polishing an irregularly contoured article without major tool changes.

An additional object of my invention has been to provide a means for preventing ware impingement or contact during a polishing operation and thereby eliminating Ware-to-ware breakage.

Another object of my invention has been to reduce the amount of media and abrasive used, many types of which are expensive; thus reducing costs.

It has been another object of my invention to tailor the chamber size and contour to fit desired ware size and contour.

It has been a further object of my invention to achieve and produce a higher and more uniform cutting rate.

An additional object of my invention has been to remove scale from Ware articles, such as foreign material picked up by article before article can be removed from mold.

It has been a further object of my invention to find more efficient modes of vibration.

An additional object of my invention has been to provide an apparatus to remove seams and flash troughs from ware articles economically and suitably adaptable to production requirements.

Other objects and advantages of this invention will be shown in the following detailed description of a preferred embodiment thereof as illustrated in the accompanying drawing in which:

FIG. 1 is a top plan view of a chamber embodying my invention.

FIG. 2 is a front elevational view of the chamber embodying my invention.

FIG. 3 shows a form of apparatus embodying the invention in side elevation and partly in section, with a ware article mounted therein.

FIG. 4 is a side sectional view illustrating another form of a device for finishing articles affixed to a lid portion in which the chamber is interiorly shaped to conform to the exterior configurations of an article being finished; and an alternate means is provided to rigidly hold the article.

Referring now to the drawing and particularly FIG. 3, the number 5 represents commercial vibrator means, such as a model manufactured by Vibrodyne, Inc., 125 Sunrise Place, Dayton 7, Ohio. Operation of said unit is described in said companys bulletin 301 and pictured in Vibrodyne, Inc., drawing No. VS 350. Commercial vibrator unit 5 provides a variable shape force from a main vibratory source. One end of a rigid connecting beam 7, which is formed from a suitably tough material, is suitably coupled to the main vibratory source of unit 5 for receiving and transmitting vibratory power therefrom. The other end of rigid beam 7 is attached to a chamber 9 and retained in place by suitable means so that vibrator unit 5 and the chamber 9 embody a rigid assembly. Such assembly thus provides an adjustable, variable amplitude of shaking force to the chamber 9.

In a preferred embodiment of my invention the exterior configuration of the chamber 9 is that of a rectangular box, however, any suitable exterior shape may be employed. Bottom portion 11 of chamber 9, is shown having an elliptically-shaped cylindrical trough section 13 disposed longitudinally within chamber 9, and suitably affixed to lower sidewalls 15 and 17 (shown in FIG. 2). In FIG. 3 lid portion 19 of chamber 9 is shown having an elliptically-shaped cylindrical dome section 21 disposed longitudinally within chamber 9, and suitably aflixed to upper sidewalls 23 and 25 (as shown in FIG. 2).

As shown particularly in FIG. 1, a media admitting port 27 in lid portion 19 provides for the admission of the media and the other additives. The bottom portion 11 and lid portion 19 are suitably united and aflixed to one another to form chamber 9.

A suitably demountable, ware retaining means 29 is mounted within trough section 13 and dome section 21. Ware articles 31, such as cups in the preferred embodiment, are detachably mounted to a ware retaining head assembly H which prevents the entry of the media and other additives from entering the interior of the cup during operation. It is within the scope of the present invention that the ware articles be maintained in desired positionment on the ware retaining head assembly H during operation by a suction device, friction or mechanical clamping device.

In the example shown in FIG. 1, the head H assembly is provided with subatmospheric pressure such as by vacuum pump P, to create a vacuum Within the cup, and thus retain the cup upon the head. However, if desired, the head H may be provided with an inflatable, hollow memher which, upon application of pressure, expands outwardly within the cup to securely grasp and maintain the cup upon the head. If desired an adhesive coating may be applied to the outer surface of ware retaining assembly H to provide a frictional adhesion of the smooth inner surface of the ware article to the adhesive layer.

Clamping of the ware is necessary to get an efficient operation, and to prevent ware-to-ware impingement or contact which causes breakage. Clamping further results in faster and more eflicient cutting rates. A shaft 34 engages ware retaining head assembly H.

In FIG. 3 the chamber 9 containing a mounted ware article 31 is shown rigidly affixed to commercial vibrator unit 5. In operation a suitable abrasive compound including media 3 6, such as abrasive nuggets, are vibrated to cascade in the direction shown by the arrow around the mounted ware articles 31. Localized finishing is accomplished by continued impinging shocks and abrasions upon the ware by the media flowing along the ware surface.

Internal chamber configuration and size is tailored to approximate the contour and dimensions of a Ware article. The distance between the sidewalls and the mounted ware is minimized, thus reducing the amount of media necessary to accomplish the finishing operation. By reducing the amount of media and abrasive, the process is more efficient. Known tub methods of finishing depend on gravity forces influencing the falling media which produce a scrubbing action. By internally contouring an enclosed chamber, the media, the mounted ware articles and the contoured walls are closely spaced thus reducing the dependence upon gravity forces. The internal curvature of the chamber effects the orbital motion of the media; said orbital motion is the result of an induced angular force received from the angular displacement of the chamber, With fixtured ware in a contoured chamber, the major force is in the form of an impact force, made up of an impulse force and a momentum force. The forces developed in the system are dependent on momentum and the change in momentum after impact. A method for measuring the momentum change is to measure the relative velocity changes of the media before and after the impact. This change in the relative velocity is sometimes called the coefiicient of restitution. Further, by contouring the chamber, the media displacement is restricted. This media restriction has the effect of producing a higher and more uniform cutting rate.

It is within the course and scope of this invention to construct shaft 34 with flexible material of such length and thickness that vibration of the chamber causes the shaft to oscillate as a reed or pendulum, thus oscillating the Ware as shown by the double-headed arrow in FIG. 3. As such the shaft and its appendages resonate within the chamber and improve the cutting rates.

In an alternative embodiment illustrated in FIG. 4, the demountable ware retaining means 29 is suitably mounted to lid portion 19. The shaft 34 of retaining means 29 engages ware retaining head assembly H. The longitudinal axis of head assembly H is perpendicular to connecting beam 7. The ware head assembly H comprises a longitudinally oriented, ware plug core 38. A contoured plug 40 of flexible or resilient material, shaped to frictionally complement the contour of the interior surface of the ware articles 31, is positioned about the ware plug core 38.

A ware holddown assembly B is illustrated on the alternate embodiment in FIG. 4. The holddown assembly is suitably attached to a sidewall of the chamber 9 for urging a ware article to remain in a fixed position on retaining head assembly H during the finishing operation.

The ware holddown assembly B comprises bearing means 44 secured to sidewalls of the chamber. An axially adjustable or reciprocable rod 46, which may be actuated by a conventional hydraulic or pneumatic means or threaded arrangement is dependently supported by each bearing means 44. A desired preset pressure may be applied to hold the ware article in a desired positionment during the entire grinding and honing operation. The reciprocable rods 46 are mounted in an axial relationship to the longitudinal axis of ware plug core 38. A resilient holddown pad 48, adapted to engage a ware article, is secured to an internal end of each axially reciprocable rod 46.

The lateral motion of axially reciprocable rods 46 is of a length suitable to provide for the mounting and demounting of ware articles on the head assembly. In a preferred embodiment of a cup-finishing chamber, the cup handle is mounted in a position wherein the handle will be substantially horizontal and in a direction away from vibrator means 5. The pressure on reciprocable rods 46 may be present. In all events, the pressure exerted by rods 46 is of sufficient force to maintain the ware article in a fixed positionment during the entire finishing cycle. Fixed positionment yields the highest and most uniform cutting rates and enhances the efiiciency of the system.

The internal configuration of the chamber 9' in FIG. 4 is contoured to reduce the amount of media and additives necessary and to provide a more uniform flow of the media. A lower contoured liner 50 of a suitable material is secured to bottom portion 11. An upper contoured liner 52 of a suitable material is secured to lid portion 19. The contoured liners 50 and 52 are arc-shaped to complement the longitudinal contour of the exterior surface of the ware article 31. The contour is thus frusto-ellipsoidal as an ellipsoid which is truncated at both extremities of the major axis and has plane surfaces parallel to the minor axis. Positionment of the liners 50 and 52 and the ware article is such that a suflicient amount of media is allowed to pass therebetween during the vibrating of the chamber 9.

It thus can be seen that in carrying out my inventive concept a contoured chamber is coupled with a commercial vibrator unit to selectively finish the exterior surface of a suitably mounted, irregularly contoured ware article. The chamber is designed for maximum utilization of materials. The media and additives are vibrated and flow with a circular pattern around the mounted article.

Although the present invention has been described with respect to specific details of certain embodiments thereof, it is not intended that such details be limitations upon the scope of the invention except insofar as set forth in the following claims.

I claim:

1. Improved vibratory finishing apparatus for smoothly grinding outer surfaces of cup-shaped articles and the like comprising; a contoured chamber having rounded inner wall portions to complementarily enclose a cup-like article to be finished, an upper cover member closing said contoured chamber having rounded wall portions which complementarily continue said rounded inner wall portions of said contoured chamber, retaining means within said chamber for operably retaining ware articles; abrasive means within said chamber; a rigid connecting beam attached to said chamber in a perpendicular relationship to a longitudinal axis of the chamber and said retaining means; vibrator means coupled with said connecting beam for vibrating said chamber and operatively inducing said abrasive means to orbit about the article; and flexible shaft means connecting said retaining means to said chamber wall for transmitting vibration from said chamber to said retaining means to cause said ware to resonate relative to the chamber and thereby improve the finishing rate.

2. Improved apparatus for finishing outer surface portions of ware articles which comprises, a contoured cham ber, means attached to a wall of said chamber for flexibly mounting at least one were article within said chamber, said chamber having inner wall portions which continuously complement outer surface portions of the ware article, a removable upper cover member forming a part of said chamber, said cover member having inner wall portions which complementarily continue the contoured chamber surrounding said article, abrasive media within said chamber, means for externally vibrating said chamber and orbiting said abrasive media about said article, and said flexible mounting means being responsive to said vibrating means to simultaneously oscillate said ware article relative to said chamber and thereby facilitate the finishing operation.

References Cited UNITED STATES PATENTS 130,520 8/1872 Mellor 517 765,304 7/1904 Bishop. 1,688,424 10/1928 Kiefer 51-2$5 2,735,231 2/1956 Simjian 51-7 2,796,702 6/1957 Bodine 5 1-7 2,973,606 3/ 1961 Brandt 51-163' 3,073,069 1/1963 Balz 51-7 3,253,369 5/1966 Reichert 51--163 FOREIGN PATENTS 841,723 7/ 1960 Great Britain.

HAROLD D. WHITEHEAD, Primlary Examiner. 

1. IMPROVED VIBRATORY FININSHING APPARATUS FOR SMOOTHLY GRINDING OUTER SURFACES OF CUP-SHAPED ARTICLES AND THE LIKE COMPRISING; A CONTOURED CHAMBER HAVING ROUNDED INNER WALL PORTIONS TO COMPLEMENTARILY ENCLOSE A CUP-LIKE ARTICLE TO BE FINISHED, AN UPPER COVER MEMBER CLOSING SAID CONTOURED CHAMBER HAVING ROUNDED WALL PORTIONS WHICH COMPLEMENTARILY CONTINUE SAID ROUNDED INNER WALL PORTIONS OF SAID CONTOURED CHAMBER, RETAINING MEANS WITHIN SAID CHAMBER FOR OPERABLY RETAINING WARE ARTICLES; ABRASIVE MEANS WITHIN SAID CHAMBER; A RIGID CONNECTING BEAM ATTACHED TO SAID CHAMBER IN A PERPENDICUALR RELATIONSHIP TO 